SELECT 
  cscart_products.*, 
  cscart_products.ebay_status, 
  cscart_products.ebay_template_id 
FROM 
  cscart_products 
WHERE 
  cscart_products.product_id IN (
    8670, 8671, 8675, 8680, 8684, 8687, 8694, 
    8698, 8704, 8705, 8709, 8710, 8719, 
    8720, 8721, 8724
  )

Query time 0.00029

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "table_name": "cscart_products",
      "access_type": "range",
      "possible_keys": ["PRIMARY"],
      "key": "PRIMARY",
      "key_length": "3",
      "used_key_parts": ["product_id"],
      "rows": 16,
      "filtered": 100,
      "index_condition": "cscart_products.product_id in (8670,8671,8675,8680,8684,8687,8694,8698,8704,8705,8709,8710,8719,8720,8721,8724)"
    }
  }
}